An Ounce of Prevention...
Reducing the input error rate is one of the best ways to improve accuracy, but few firms do
it well. All the more strange because the tools and procedures are simple old stand-bys from
Work Simplification and TQM: fishbone diagrams, process charts, pareto charts, five why's and
In some firms, Root Cause Analysis consists of finding someone to blame. Real root causes are
usually systemic; not personal.
Root Causes of Inventory Record Errors
The fishbone diagram of figure 5 (a.k.a. Ishikawa chart, cause & effect chart), shows some
common inventory errors and their possible causes. The red envelopes highlight some of the more
prevalent and overlooked causes of errors. Dashed purple lines illustrate how any branch can be
expanded, digging further and further towards the real root cause.
This is not a complete summary of causes; nor does it drill down to all
root causes. It is, however, a good starting point.
"Major Strasser has been shot...
Round up the usual suspects!"
Figure 5-- Inventory Error Causes